1. Field of the Invention
The present invention generally relates to a light source, and more particularly, to a light tube.
2. Description of Related Art
The power and light intensity of light-emitting diode (LED) have been increased along with the development of semiconductor technology. Moreover, LED has been broadly applied to different products (for example, illumination devices, traffic lights, displays, and optical mice, etc) and is about to replace the conventional fluorescent light tube due to its many advantages, such as low power consumption, long lifespan, environment friendliness, quick launch, and small volume.
Conventionally, a LED light tube is fastened to the base of a conventional fluorescent light tube by using a fastener. However, the fastener used for fastening the LED light tube is not conductive. Accordingly, an additional conductive wire has to be disposed for electrically connecting the circuit board in the LED light tube and the base. The conductive wire has to be manually welded to the circuit board in the LED light tube and the base in order to electrically connect the two. As a result, the assembly and disassembly of the LED light tube are very inconvenient and it is very difficult and time-consuming to replace the LED light tube.
In order to resolve foregoing problem, two electrode poles of a conventional fluorescent light tube which are suitable for being inserted into the socket on the base can be directly welded to the circuit board. However, through such a method, the problem of insufficient structure strength may be produced, and the parallelism between the two electrode poles may be adversely affected. To be specific, if the electrode poles of a LED light tube are inserted into the socket on a base and the LED light tube is turned to a fastened position through the method for assembling a conventional fluorescent light tube, the force for turning the LED light tube may break the welding points between the electrode poles and the circuit board so that the electrode poles may fall off from the circuit board. Besides, when the electrode poles are welded onto the circuit board, it is very difficult to maintain the parallelism between the two electrode poles. Thereby, such a design may reduce the production yield.
Additionally, in a conventional LED light tube, the LED is disposed in the center of the circuit board. As a result, the LED is centralized within a specific area on the circuit board. Since LED is highly directional, the light emitted by a LED light tube may be too concentrated and accordingly the LED light tube may not be suitable for illumination of general purpose if the disposition of the LED is highly centralized. Besides, if the disposition of LED is too centralized, the heat produced by the LED cannot be dissipated efficiently. As a result, the heat dissipation efficiency of the LED light tube is reduced, and accordingly the light emitting efficiency and lifespan of the LED light tube are reduced.